JP2022026335A - Optical laminate, polarizing plate, and image display device - Google Patents

Abstract

To provide an optical laminate which suppresses degradation in a dye, and can maintain visibility over a long period of time.SOLUTION: An optical laminate has a hard coat layer 30 and a base material layer 10 in this order from an outer layer side, and has at least any one configuration of the following configurations (1) and (2). (1) A dye 81 penetrated from a surface on the side of the hard coat layer 30 of the base material layer 10 or a surface opposite to the hard coat layer 30 of the base material layer 10 is contained in the base material layer 10; a resin constituting the base material layer 10 is a non-radical polymerizable resin; and an ultraviolet absorber is contained in the base material layer 10 and at least one or more layers selected from layers positioned on the outer layer side of the base material layer 10. (2) The optical laminate 100 has a resin layer 2 that contains a dye 2 and a binder resin and has a thickness of 5.0 μm or less as a layer other than the hard coat layer 30 and the base material layer 10, and the binder resin is a non-radical polymerizable resin. An ultraviolet absorber is further contained in the resin layer 2 and a layer selected from layers positioned on the outer layer side of the resin layer 2.SELECTED DRAWING: Figure 1

Description

The present invention relates to an optical laminate, a polarizing plate and an image display device.

In recent years, image display devices such as organic EL display devices, liquid crystal displays, and micro LED display devices have been developed to improve color purity and color reproducibility. In order to increase the color purity of the image display device, the distribution shape of the RGB spectrum emitted from the display element may be sharpened.
As an image display device having a sharp distribution shape of an RGB spectrum, for example, an organic EL display device using a three-color independent organic EL element, a liquid crystal display device using quantum dots for a backlight, and the like have been proposed. ..

However, the distributed shape of the spectrum of the emitted light is due to the material of the light emitting material. Therefore, in the light emitting material currently widely used, there is a certain limit in sharpening the distribution shape of the RGB spectrum of the emitted light. As a means for solving such a problem, for example, the means of Patent Document 1 has been proposed.

Japanese Patent Application Laid-Open No. 2003-191366 (Claims 1, 6, 7 and 9)

Patent Document 1 comprises a base film layer, a hard coat layer provided on one surface of the base film layer, and an adhesive layer provided on the other surface of the base film layer, and an ultraviolet absorber may be used. Disclosed is an optical laminate that is contained in the layer, has a dye-containing layer on the adhesive layer side of a layer containing an ultraviolet absorber, and has predetermined optical characteristics.
The optical laminate of Patent Document 1 aims to improve color purity by cutting light in a specific wavelength range, suppress deterioration of dyes due to ultraviolet rays, and maintain visibility for a long period of time. be.

However, even in the case of an optical laminate satisfying the constituent requirements of Patent Document 1, there are many cases where the visibility cannot be improved.

An object of the present invention is to provide an optical laminate capable of suppressing deterioration of a dye and maintaining visibility for a long period of time, and a polarizing plate and an image display device using the same.

As a result of diligent research to solve the above problems, the present inventors, when the layer containing the dye contains a radically polymerizable resin, the radicals generated during the formation of the layer and the radicals generated over time after the formation of the layer are used. We have found that the deterioration of dyes and the inability to sufficiently suppress the deterioration of dyes due to radicals with ultraviolet absorbers and light stabilizers are the causes of the above problems, and have solved this problem.

The present invention provides the following optical laminates, polarizing plates and display devices [1] to [3].
[1] An optical laminate having a hard coat layer and a substrate layer in this order from the outer layer side, and having at least one of the following configurations (1) and (2).
(1) The base material layer contains a dye 1 that has penetrated from the surface of the base material layer on the side of the hard coat layer or the surface of the base material layer on the side opposite to the hard coat layer, and the base. The resin constituting the material layer is a non-radical polymerizable resin. Further, at least one layer selected from the base material layer and the layer located on the outer layer side of the base material layer contains an ultraviolet absorber.
(2) The optical laminate has a resin layer 2 having a thickness of 5.0 μm or less containing a dye 2 and a binder resin as a layer other than the hard coat layer and the base material layer, and the binder resin is a non-radical polymerizable resin. Is. Further, at least one layer selected from the resin layer 2 and the layer located on the outer layer side of the resin layer 2 contains an ultraviolet absorber.
[2] A polarizing plate having a polarizing element, a transparent protective plate A arranged on one side of the polarizing element, and a transparent protective plate B arranged on the other side of the polarizing element. At least one of the transparent protective plate A and the transparent protective plate B is the optical laminate according to the above [1], and the optical laminate is such that the surface on the hard coat layer side faces the opposite side to the polarizing element. A polarizing plate on which the body is arranged.
[3] An image display device having a display element and the optical laminate according to the above [1] or the polarizing plate according to the above [2].

The optical laminate, the polarizing plate, and the image display device of the present invention can suppress deterioration of the dye and maintain visibility for a long period of time.

It is sectional drawing which shows one Embodiment of the optical laminated body of this invention. It is sectional drawing which shows the other embodiment of the optical laminated body of this invention. It is sectional drawing which shows the other embodiment of the optical laminated body of this invention. It is sectional drawing which shows the other embodiment of the optical laminated body of this invention. It is sectional drawing which shows one Embodiment of the image display device of this invention. It is a figure which shows one Embodiment of the measured value of the spectral transmittance of an optical laminated body.

Hereinafter, embodiments of the present invention will be described.
[Optical laminate]
The optical laminate of the present invention has a hard coat layer and a base material layer in this order from the outer layer side, and has at least one of the following configurations (1) and (2).
(1) The base material layer contains a dye 1 that has penetrated from the surface of the base material layer on the side of the hard coat layer or the surface of the base material layer on the side opposite to the hard coat layer, and the base. The resin constituting the material layer is a non-radical polymerizable resin. Further, at least one layer selected from the base material layer and the layer located on the outer layer side of the base material layer contains an ultraviolet absorber.
(2) The optical laminate has a resin layer 2 having a thickness of 5.0 μm or less containing a dye 2 and a binder resin as a layer other than the hard coat layer and the base material layer, and the binder resin is a non-radical polymerizable resin. Is. Further, at least one layer selected from the resin layer 2 and the layer located on the outer layer side of the resin layer 2 contains an ultraviolet absorber.

Hereinafter, the optical laminate having the configuration of the above (1) will be described as the first embodiment, and the optical laminate having the configuration of the above (2) will be described as the second embodiment.

-Optical laminate of Embodiment 1-
The optical laminate of the first embodiment has a hard coat layer and a base material layer in this order from the outer layer side, and has the configuration of the following (1).
(1) The base material layer contains a dye 1 that has penetrated from the surface of the base material layer on the side of the hard coat layer or the surface of the base material layer on the side opposite to the hard coat layer, and the base. The resin constituting the material layer is a non-radical polymerizable resin. Further, at least one layer selected from the base material layer and the layer located on the outer layer side of the base material layer contains an ultraviolet absorber.

In the first embodiment, it is required that the base material layer contains the dye 1 which has penetrated from the surface of the base material layer on the hard coat layer side or the surface of the base material layer opposite to the hard coat layer. Hereinafter, the dye 1 that permeates from the surface of the base material layer on the hard coat layer side or the surface of the base material layer opposite to the hard coat layer is referred to as a “penetration dye”.
When the base material layer contains a dye from the beginning, the dye tends to seep out when another layer such as a hard coat layer is laminated on the base material layer, and the visibility may be deteriorated. Hereinafter, the dye contained in the base material layer from the beginning is referred to as a "base material-containing dye". The reason why the base material-containing dye easily exudes from the base material layer when another layer is formed on the base material layer is that many dyes have a low molecular weight. In the optical laminate of Patent Document 1, since the base film contains the base-containing dye, the base-containing dye seeps out when the hard coat layer or the like is formed, and the visibility is deteriorated.
Therefore, in the first embodiment, the dye 1 in the base material layer penetrates from the surface of the base material layer on the hard coat layer side or the surface of the base material layer opposite to the hard coat layer (penetration dye 1). ). In the first embodiment, it is preferable that the base material layer does not substantially contain the base material-containing dye. Specifically, in the first embodiment, the content of the base material-containing dye in the base material layer is preferably 0.1% by mass or less of the total solid content of the base material layer, and more preferably 0.01. It is 0% by mass or less, more preferably 0% by mass.

As a means for infiltrating the dye into the base material layer, for example, a means for applying an ink containing the dye and the solvent on the base material layer which is easily dissolved or swollen with a solvent can be mentioned.
The ink may not contain resin or may contain resin. When an ink containing a dye and a solvent and not containing a resin is applied onto a base material layer that easily dissolves or swells with a solvent, most of the dye permeates into the base material layer and becomes a penetrating dye (dye 1). .. Further, when an ink containing a dye, a solvent and a resin is applied on a base material layer that easily dissolves or swells with a solvent, most of the dye permeates into the base material layer, while the resin has a large molecular weight, so that the base material It does not easily penetrate into the layer and forms a resin coating film on the base material layer. Therefore, for example, by incorporating a dye in the ink for forming the hard coat layer, the dye permeates into the base material layer when the hard coat layer is formed, and becomes a penetrating dye (dye 1).

Further, in the first embodiment, the resin constituting the base material layer is required to be a non-radical polymerizable resin. When the resin constituting the base material layer is a radically polymerizable resin, the penetrating dye (dye 1) is deteriorated by the radicals generated from the radically polymerizable resin over time.
As used herein, the term "radical polymerizable resin" means "a cured product of a composition containing a radically polymerizable compound". Specific examples of the radically polymerizable compound will be described later.

Further, in the first embodiment, it is required that at least one of the base material layer and the layer located on the outer layer side of the base material layer contains the ultraviolet absorber. Without this configuration, the penetrating dye (dye 1) in the substrate layer deteriorates over time.

1 and 2 are cross-sectional views showing an embodiment of the optical laminate (100) of the first embodiment.
The optical laminate (100) of FIGS. 1 and 2 has a hard coat layer (30) and a base material layer (10) in this order from the outer layer side.
Further, the optical laminate (100) of FIG. 1 contains the dye 1 (81) which has penetrated from the surface of the base material layer (30) on the hard coat layer (30) side in the base material layer (10) and is hard. The coat layer (30) contains an ultraviolet absorber (70). The base material layer (10) of the optical laminate of FIG. 1 has a dye permeation region (12) on the hard coat layer (30) side, and a dye non-permeation region (11) is a hard coat layer. It is held on the opposite side of (30). Further, the optical laminate (100) of FIG. 1 has a resin layer 1 (21) between the hard coat layer (30) and the base material layer (10).
Further, the optical laminate (100) of FIG. 2 contains an ultraviolet absorber (70) in the base material layer (10) and penetrates from the surface of the base material layer opposite to the hard coat layer (30). It contains dye 1 (81). The base material layer (10) of the optical laminate of FIG. 2 has a dye permeation region (12) in which the dye permeates on the opposite side of the hard coat layer (30), and has a dye non-permeation region (11). It is provided on the hard coat layer (30) side.
When the dye 1 (81) permeates into the base material layer (10), the surface of the base material layer (10) on the side where the dye (81) has invaded is usually in a rough state. That is, in the case of the layer structure of FIG. 1, the surface of the base material layer (10) on the hard coat layer side is usually in a rough state, but in FIG. 1, in order to simplify the drawing, the base material layer (10) is shown. The surface of the hardcourt layer side is shown smooth. Similarly, in the case of the layer structure of FIG. 2, the surface of the base material layer (10) opposite to the hard coat layer is usually in a rough state, but in FIG. 2, in order to simplify the drawing, the base material is used. The surface of the layer (10) on the opposite side of the hard coat layer is shown smooth.
The optical laminate of the first embodiment is not limited to the configurations shown in FIGS. 1 and 2. For example, in the configuration of FIG. 1, the optical laminate of the first embodiment may have a configuration in which the hard coat layer (30) and the base material layer (10) are in contact with each other without the resin layer 1 (21). .. Further, in the configuration of FIG. 2, the optical laminate of the first embodiment may contain an ultraviolet absorber (70) in the hard coat layer (30). Further, the optical laminated body of the first embodiment may have a laminated structure different from the laminated structure of FIGS. 1 and 2.

<Dye 1>
Dye 1 includes phthalocyanine-based, cyanine-based, squarylium-based, indole compound-based, azomethine-based, xanthene-based, oxonol-based, azo-based, quinone-based, azulenium-based, pyrylium-based, croconium-based, pyrromethene-based, and porphyrin-based organic. Examples include system dyes. These organic dyes can be used alone or in combination of two or more. Among these, porphyrin-based organic dyes are preferable because of their narrow absorption peak wavelength, excellent solubility in organic solvents, and good light resistance, and tetraazaporphyrin-based organic dyes are preferable. More preferred.

The content of the dye 1 (penetrating dye) is preferably 0.001 to 0.500 g / m ² and 0.001 to 0.150 g / m ² in terms of the unit area of the optical laminate. It is more preferable to have.

In the first embodiment, the content of the dye 1 (penetrating dye) varies depending on the thickness of the base material layer and cannot be unequivocally determined, but is 0.01 to 10 parts by mass with respect to 100 parts by mass of the resin in the base material layer. It is preferably 0.05 to 2.0 parts by mass, and more preferably 0.05 to 2.0 parts by mass.

In the first embodiment, the dye 1 (penetration dye) preferably has a molecular weight of 1,000 or less, and more preferably 400 or less, from the viewpoint of facilitating penetration into the base material layer. The lower limit of the molecular weight of the dye 1 (penetrating dye) is not particularly limited, but is usually 200 or more.

<Base layer>
In the first embodiment, the resin constituting the base material layer needs to be a non-radical polymerizable resin. In other words, in the first embodiment, the base material layer is required to be a plastic film formed of a non-radical polymerizable resin.
Examples of the non-radical polymerizable resin include acrylics such as polymethyl methacrylate, triacetyl cellulose (TAC), cellulose diacetate, cellulose acetate butyrate, polyester, polyamide, polyimide, polyamideimide, polyaramid, polyether sulphon, and polysulphon. Examples thereof include polypropylene, polymethylpentene, polyvinyl chloride, polyvinyl acetatel, polyether ketone, polycarbonate, polyurethane and amorphous olefin (Cyclo-Olfin-Polymer: COP).

Further, in the first embodiment, it is preferable that the base material layer is easily dissolved or swollen with a solvent. By applying an ink containing a dye and a solvent on a base material layer that easily dissolves or swells with a solvent, the dye can be easily permeated into the base material layer, and the configuration of the first embodiment can be easily realized. ..

An acrylic film or a triacetyl cellulose film is preferable as the base material layer that easily dissolves or swells with a solvent. The triacetyl cellulose film is more preferable because it easily dissolves or swells in a solvent. Further, the acrylic film is preferable in that the penetrating dye does not easily bleed out. Acrylic films and triacetyl cellulose films are also preferable in that the in-plane retardation can be easily reduced.
Even for a base material layer other than the acrylic film and the triacetyl cellulose film (for example, polyimide, polyamide, polyamideimide, polyaramid), the dye can be permeated into the base material by selecting an appropriate solvent. can.

The solvent contained in the ink containing the dye and the solvent is preferably one that dissolves or swells the base material layer, but if the base material layer is excessively dissolved or swelled, the strength of the base material layer decreases. Therefore, it is preferable to use an appropriate solvent contained in the ink containing the dye and the solvent, depending on the resin constituting the base material layer.
For example, when the base material layer is an acrylic film, a solvent containing a solvent that does not easily volatilize is preferable. When the base material layer is a triacetyl cellulose film, a solvent containing methyl isobutyl ketone (MIBK) is preferable.
In addition, toluene and cyclohexanone tend to excessively dissolve or swell acrylic. Therefore, when the base material layer is an acrylic film, the content ratio of toluene and cyclohexanone in the total solvent is preferably less than 70% by mass. In addition, methyl ethyl ketone (MEK) and methyl acetate tend to excessively dissolve or swell triacetyl cellulose. Therefore, when the base material layer is a triacetyl cellulose film, the content ratio of MEK and methyl acetate in the total solvent is preferably less than 70% by mass.

In the first embodiment, the base material layer is divided into two regions in the thickness direction, the region on the hard coat layer side is defined as H, and the region on the side opposite to the hard coat layer is defined as L. Further, the average concentration of the dye 1 (penetrating dye) in the region H on the hard coat layer side is defined as DH, and the average concentration of the dye 1 (penetrating dye) in the region L on the opposite side of the hard coat layer is defined as DL.
Under the above preconditions, when the dye permeates from the surface of the base material layer on the hard coat layer side, it is preferable to satisfy the relationship of DL <DH, which is on the side opposite to the hard coat layer of the base material layer. When the dye permeates from the surface, it is preferable to satisfy the relationship of DH <DL. By satisfying this relationship, it is possible to easily suppress a decrease in the strength of the base material layer due to excessive penetration of the dye into the base material layer.
Further, under the above preconditions, when the dye has penetrated from the surface of the base material layer on the hard coat layer side, it is preferable that the region L does not substantially contain the dye 1 (penetrating dye). When the dye has penetrated from the surface of the material layer opposite to the hard coat layer, it is preferable that the region H does not substantially contain the dye 1 (penetrating dye). By satisfying this relationship, it is possible to more easily suppress a decrease in the strength of the base material layer. The fact that the region L (or the region H) does not substantially contain the dye 1 (penetrating dye) means that the content of the dye 1 (penetrating dye) with respect to the total solid content of the region L (or the region H) is 0.1% by mass. It means that it is less than or equal to, preferably 0.01% by mass or less, and more preferably 0% by mass.
When the dye has penetrated from the surface of the base material layer on the hard coat layer side, a resin layer (resin layer) containing a non-radical polymerizable resin as a main component between the base material layer and the hard coat layer. It is preferable to arrange 1). By arranging the resin layer 1 between the base material layer and the hard coat layer, the dye permeates from the surface of the base material layer on the hard coat layer side, and the relationship of DL <DH is established. In the case of filling, the radically polymerizable resin of the hard coat layer can easily suppress the deterioration of the penetrating dye of the base material layer. The resin layer (resin layer 1) containing a non-radical polymerizable resin as a main component will be described later.

The lower limit of the thickness of the base material layer is preferably 3 μm or more, more preferably 10 μm or more, still more preferably 20 μm or more, and the upper limit is preferably 300 μm or less, more preferably 20 μm or less, still more preferably 100 μm or less, still more preferably. It is 70 μm or less, more preferably 45 μm or less, still more preferably 30 μm or less.

In the present specification, for each thickness contained in the optical laminate such as the base material layer and the hard coat layer, for example, 20 points are selected from arbitrary points in the cross-sectional photograph of the optical laminate by a scanning transmission electron microscope (STEM). It can be calculated from the average value. The acceleration voltage and magnification of the STEM can be appropriately adjusted according to the sample, and for example, the acceleration voltage is preferably 10 kv to 30 kV and the magnification is preferably 1000 to 7000 times.
The variation in the thickness of the base material layer is preferably in the range of ± 8% on average, more preferably in the range of ± 4% on average, and even more preferably in the range of ± 3% on average. .. For example, if the average thickness is 50 μm, each thickness is preferably within the range of 46 to 54 μm, each thickness is preferably within the range of 48 to 52 μm, and each thickness is 48.5 to 51. It is more preferable to stay within the range of .5 μm.

The surface of the base material layer may be subjected to physical treatment such as corona discharge treatment or chemical treatment, or an easy-adhesion layer may be formed in order to improve the adhesiveness.

The base material layer preferably has high light transmission. Specifically, the base material layer preferably has a total light transmittance of JIS K7361-1: 1997 of 80% or more, more preferably 85% or more, and further preferably 90% or more. ..

<UV absorber>
The optical laminate of the first embodiment requires that the ultraviolet absorber is contained in at least one layer selected from the base material layer and the layer located on the outer layer side of the base material layer. Without this configuration, the dye 1 (penetration dye) in the substrate layer deteriorates over time.

In the first embodiment, the ultraviolet absorber may be contained only in the base material layer, or the ultraviolet absorber may be contained only in the layer located on the outer layer side of the base material layer, and both of them may contain the ultraviolet absorber. May include. Examples of the layer located on the outer layer side of the base material layer include a hard coat layer, a resin layer 1, an antireflection layer and the like.

In the first and second embodiments, when the base material layer contains an ultraviolet absorber, the ultraviolet absorber may be contained in the base material layer from the beginning, or the hard coat layer side of the base material layer. It may be an ultraviolet absorber that penetrates from the surface of the base material or the surface of the base material opposite to the hard coat layer.
In the first and second embodiments, the ultraviolet absorber contained in the base material layer from the beginning is preferably one having a high molecular weight.
Further, in the first and second embodiments, when the ultraviolet absorber penetrating into the base material layer is contained, the ultraviolet absorber permeates from the surface of the base material layer on the hard coat layer side. It is preferably an agent.

In the first and second embodiments, when the base material layer contains an ultraviolet absorber that permeates from the surface on the hard coat layer side, the ultraviolet absorber in the region H on the hard coat layer side of the base material layer. When the average concentration is defined as UH and the average concentration of the ultraviolet absorber in the region L opposite to the hardcourt layer of the substrate layer is defined as UL, it is preferable to satisfy the relationship of UL <UH. By satisfying this relationship, it is possible to easily suppress a decrease in the strength of the base material layer due to excessive penetration of the ultraviolet absorber into the base material layer.
Further, in the preferred embodiments of the first and second embodiments, it is preferable that the region L does not substantially contain an ultraviolet absorber. By satisfying this relationship, it is possible to more easily suppress a decrease in the strength of the base material layer. The fact that the region L does not substantially contain the ultraviolet absorber means that the content of the ultraviolet absorber with respect to the total solid content of the region L is 0.1% by mass or less, preferably 0.01% by mass or less. It is more preferably 0% by mass.
Further, in the preferred embodiment of the first embodiment (the embodiment in which the base material layer contains an ultraviolet absorber that permeates from the surface on the hard coat layer side), the penetrating dye in the base material layer is the hard coat layer. Is preferably made by penetrating from the opposite surface. With this configuration, deterioration of the dye can be more easily suppressed.

In the first and second embodiments, the ultraviolet absorbers include general-purpose benzotriazole-based ultraviolet absorbers, triazine-based ultraviolet absorbers, benzoxazinone-based ultraviolet absorbers, benzophenone-based ultraviolet absorbers, anthracene-based ultraviolet absorbers, and the like. One or more of the organic ultraviolet absorbers of the above can be used.

In the first and second embodiments, when the ultraviolet absorber penetrating into the base material layer is contained, the molecular weight of the ultraviolet absorber is preferably 2,000 or less, more preferably 800 or less. .. The molecular weight of the ultraviolet absorber is preferably 200 or more.
Further, in the first embodiment, it is preferable that the molecular weight of the ultraviolet absorber that permeates into the base material layer is larger than the molecular weight of the dye 1 (penetrating dye). When an ink containing an ultraviolet absorber and a dye satisfying these conditions is applied to the surface of the base material layer on the hard coat layer side, the dye penetrates into the inside of the base material layer rather than the ultraviolet absorber, so that the ultraviolet absorber is used. The effect of suppressing deterioration of dye 1 (penetration dye) can be enhanced.

In the first and second embodiments, when the base material layer contains an ultraviolet absorber from the beginning, the ultraviolet absorber is prevented from seeping out when another layer is formed on the base material layer. The molecular weight of the ultraviolet absorber is preferably 300 or more, more preferably 500 or more. The molecular weight of the ultraviolet absorber is preferably 2000 or less.

In the first and second embodiments, when the UV absorber is contained in the hard coat layer, the content of the UV absorber is preferably 0.01 to 30 parts by mass with respect to 100 parts by mass of the binder resin of the hard coat layer. , 0.01 to 15 parts by mass is more preferable, and 0.5 to 10 parts by mass is further preferable.
In the first and second embodiments, when the base material layer contains an ultraviolet absorber, the content of the ultraviolet absorber is preferably 0.01 to 10 parts by mass with respect to 100 parts by mass of the binder resin of the base material layer. , 0.01 to 5 parts by mass is more preferable, and 0.01 to 3 parts by mass is further preferable.

<Hard coat layer>
The optical laminates of the first and second embodiments have a hardcourt layer.
The hardcoat layer usually contains a radically polymerizable resin. Then, the radically polymerizable resin generates radicals that cause deterioration of the dye during and after the formation of the hard coat layer. Therefore, when the dye is contained in the hard coat layer, the dye is easily deteriorated by the radicals generated in the hard coat layer.
On the other hand, since the optical laminate of the first embodiment contains the dye 1 (penetration dye) in the base material layer instead of the hard coat layer, the dye 1 (penetration) by radicals generated from the radically polymerizable resin of the hard coat layer. Deterioration of dye) can be easily suppressed.
Further, since the optical laminate of the second embodiment contains the dye 2 in the resin layer 2 instead of the hard coat layer, it is possible to easily suppress the deterioration of the dye 2 due to the radical generated from the radically polymerizable resin in the hard coat layer. ..

Hereinafter, the hard coat layer will be described in common with the first and second embodiments unless otherwise specified.
The hard coat layer preferably contains a radically polymerizable resin from the viewpoint of improving the scratch resistance of the optical laminate. As described above, the "radical polymerizable resin" means a "cured product of a composition containing a radically polymerizable compound".
The content ratio of the radically polymerizable resin to the total resin components of the hard coat layer is preferably 50% by mass or more, more preferably 70% by mass or more, still more preferably 90% by mass or more, and 95% by mass. % Or more, more preferably 99% by mass or more.

The radically polymerizable compound refers to a compound having a radically polymerizable functional group in the molecule.
Examples of the radically polymerizable functional group include ethylenically unsaturated bond-containing groups such as (meth) acryloyl group, vinyl group and allylic group. Among them, from the viewpoint of scratch resistance of the hard coat layer, the radically polymerizable compound is preferably a compound having two or more ethylenically unsaturated bond-containing groups in the molecule, and two (meth) acryloyl groups in the molecule. A polyfunctional (meth) acrylate compound having one or more is more preferable. As the polyfunctional (meth) acrylate compound, any of a monomer, an oligomer, and a polymer can be used, but from the viewpoint of scratch resistance, it is preferable to contain at least a polyfunctional (meth) acrylate monomer.

Among the polyfunctional (meth) acrylate compounds, the bifunctional (meth) acrylate monomer includes ethylene glycol di (meth) acrylate, bisphenol A tetraethoxydiacrylate, bisphenol A tetrapropoxydiacrylate, and 1,6-hexanediol diacrylate. And so on.
Examples of the trifunctional or higher functional (meth) acrylate monomer include trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, and dipenta. Examples thereof include erythritol tetra (meth) acrylate and isocyanuric acid-modified tri (meth) acrylate.
Further, the (meth) acrylate monomer may be one in which a part of the molecular skeleton is modified, and is modified with ethylene oxide, propylene oxide, caprolactone, isocyanuric acid, alkyl, cyclic alkyl, aromatic, bisphenol and the like. Things can also be used.

The polyfunctional (meth) acrylate oligomer is not particularly limited as long as it is a bifunctional or higher functional (meth) acrylate-based oligomer. For example, urethane (meth) acrylate oligomer, epoxy (meth) acrylate oligomer, polyester (meth). Examples thereof include various (meth) acrylate-based oligomers such as acrylate oligomers and polyether (meth) acrylate oligomers.
Urethane (meth) acrylate oligomers are obtained, for example, by reacting polyhydric alcohols and organic diisocyanates with hydroxy (meth) acrylates.
Further, the preferred epoxy (meth) acrylate oligomer is a (meth) acrylate obtained by reacting a trifunctional or higher functional aromatic epoxy resin, an alicyclic epoxy resin, an aliphatic epoxy resin, or the like with a (meth) acrylic acid. A (meth) acrylate obtained by reacting a polybasic acid with a polybasic acid and a (meth) acrylic acid with a functional or higher aromatic epoxy resin, an alicyclic epoxy resin, an aliphatic epoxy resin, etc., and a bifunctional or higher functional aromatic epoxy resin. , An alicyclic epoxy resin, an aliphatic epoxy resin, etc., and a (meth) acrylate obtained by reacting phenols with (meth) acrylic acid.

The polyfunctional (meth) acrylate oligomer preferably has a weight average molecular weight (polystyrene-equivalent weight average molecular weight measured by the GPC method) of less than 4,000, more preferably more than 1,000 and less than 3,000.
The polyfunctional (meth) acrylate oligomer is more preferably 3 to 12 functional, and even more preferably 3 to 10 functional. When the number of functional groups is within the above range, a protective layer having excellent strength can be obtained.

The polyfunctional (meth) acrylate polymer is not particularly limited as long as it is a bifunctional or higher functional (meth) acrylate polymer, for example, urethane (meth) acrylate polymer, epoxy (meth) acrylate polymer, polyester (meth) acrylate polymer. , Various (meth) acrylate-based polymers such as polyether (meth) acrylate polymers can be used.

The polyfunctional (meth) acrylate polymer preferably has a weight average molecular weight (polystyrene-equivalent weight average molecular weight measured by the GPC method) of 4,000 or more, preferably 10,000 to 100, from the viewpoint of obtaining the above effects. 000, more preferably 10,000 to 50,000. When the weight average molecular weight is 100,000 or less, the curability and coatability are good.
The number of functional groups of the polyfunctional (meth) acrylate polymer is not particularly limited, but from the viewpoint of curability, it is preferable that the number of functional groups per molecule is large (that is, the functional group equivalent is low). The functional group equivalent of the polyfunctional (meth) acrylate polymer is preferably 400 g / equivalent or less, more preferably 300 g / equivalent or less, still more preferably 250 g / equivalent or less.

The above radically polymerizable compounds may be used alone or in combination of two or more.
Among them, the radically polymerizable compound preferably contains the above-mentioned polyfunctional (meth) acrylate monomer as a main component from the viewpoint of scratch resistance. The content thereof is preferably 50% by mass or more, more preferably 70 to 100% by mass, still more preferably 85 to 100% by mass, based on the total amount of the radically polymerizable compound.

The composition containing the radically polymerizable compound preferably contains a photoradical polymerization initiator.
Examples of the photoradical polymerization initiator include one or more selected from acetophenone, benzophenone, α-hydroxyalkylphenone, Michler ketone, benzoin, benzylmethyl ketal, benzoyl benzoate, α-acyloxime ester, thioxanthones and the like.

The hard coat layer may contain an ultraviolet absorber as described above.
Further, the hard coat layer may contain various additives as long as the effects of the present invention are not impaired. Examples of the additive include a light stabilizer, an antioxidant, a refractive index adjusting agent, an antiglare agent, an antifouling agent, an antistatic agent, a leveling agent and the like.

The thickness of the hard coat layer is preferably 0.5 to 100 μm, more preferably 1.0 to 50 μm, and further 2.0 to 2.0, from the viewpoint of curl suppression, mechanical strength, hardness, and toughness. 20 μm is more preferable.

In the present specification, the variation in the thickness of the hard coat layer is preferably within ± 15%, more preferably within ± 10%, and even more preferably within ± 7% with respect to the average thickness. ..

<Other layers>
The optical laminate of the first embodiment may have a layer (other layer) other than the base material layer and the hard coat layer. Examples of other layers include a resin layer 1, an antireflection layer, and an adhesive layer. Further, the optical laminate of the first embodiment may have the resin layer 2 included in the optical laminate of the second embodiment.

<< Resin layer 1 >>
The optical laminate of the first embodiment is a resin layer (resin) containing a non-radical polymerizable resin as a main component between the base material layer and the hard coat layer from the viewpoint of further suppressing the deterioration of the dye 1 (penetration dye). It is preferable to have the layer 1).
Further, in the case where the resin layer 2 is provided between the base material layer and the hard coat layer in the optical laminate of the second embodiment, the hard coat layer and the resin layer 2 are combined from the viewpoint of further suppressing the deterioration of the dye 2. It is preferable to have a resin layer (resin layer 1) containing a non-radical polymerizable resin as a main component between the two.

"Containing a non-radical polymerizable resin as a main component" means that the content of the non-radical polymerizable resin in the resin layer 1 is 50% by mass or more based on the total amount of the resin layer 1, and is preferably 70. It is by mass% or more, more preferably 90% by mass or more.

The non-radical polymerizable resin preferably contains at least one selected from a cured product of a thermoplastic resin and a thermosetting resin composition. Among these, a thermoplastic resin is preferable from the viewpoint of adhesion to the base material layer, the hard coat layer and the like.

Examples of the thermoplastic resin as the non-radical polymerizable resin include acrylic resin, cellulose resin, urethane resin, vinyl chloride resin, polyester resin, polyolefin resin, polycarbonate, nylon, polystyrene, ABS resin and the like. .. Among these, an acrylic resin is preferable, and among the acrylic resins, polymethylmethacrylate (PMMA) is preferable.
Further, the thermoplastic resin preferably has a polystyrene-equivalent weight average molecular weight measured by the GPC method of 5,000 to 5 million, more preferably 10,000 to 1 million.

The cured product of the thermosetting resin composition as a non-radical polymerizable resin is a cured product of the composition containing the thermosetting resin. Examples of the thermosetting resin include acrylic resin, urethane resin, phenol resin, urea melamine resin, epoxy resin, unsaturated polyester resin, silicone resin and the like. To the thermosetting resin composition, a curing agent such as an isocyanate-based curing agent is added to these curable resins, if necessary.

The lower limit of the thickness of the resin layer 1 is preferably 1 μm or more, more preferably 3 μm or more, and the upper limit is preferably 50 μm or less, more preferably 15 μm or less.
By setting the thickness of the resin layer 1 to 1 μm or more, deterioration of the dye 1 and the dye 2 can be easily suppressed. Further, by setting the thickness of the resin layer 1 to 50 μm or less, it is possible to easily suppress the decrease in the hardness of the surface on the hard coat layer side.

The resin layer 1 may contain an additive such as an ultraviolet absorber.

《Anti-reflection layer》
The optical laminates of the first and second embodiments may have an antireflection layer located on the opposite side of the base material of the hardcoat layer from the viewpoint of imparting antireflection properties.
Hereinafter, the antireflection layer, and the low-refractive index layer and the high-refractive index layer constituting the antireflection layer will be described in common with the first and second embodiments unless otherwise specified.

Examples of the antireflection layer include a single-layer structure of a low refractive index layer and a laminated structure of a high refractive index layer and a low refractive index layer.

-Low refractive index layer-
The low refractive index layer is preferably arranged at a position farthest from the adherend among the layers constituting the transfer layer. That is, it is preferable that the low refractive index layer is arranged on the outermost surface of the molded product.
By forming a high refractive index layer, which will be described later, adjacent to the low refractive index layer on the antiglare layer side of the low refractive index layer, the antireflection property can be further enhanced.

The refractive index of the low refractive index layer is preferably 1.10 to 1.48, more preferably 1.20 to 1.45, more preferably 1.24 to 1.40, and more preferably 1.26 to 1.38. It is preferable, 1.28 to 1.35 is more preferable.
The thickness of the low refractive index layer is preferably 80 to 120 nm, more preferably 85 to 110 nm, and even more preferably 90 to 105 nm. Further, the thickness of the low refractive index layer is preferably larger than the average particle diameter of low refractive index particles such as hollow particles.

The method for forming the low refractive index layer can be roughly divided into a wet method and a dry method. As the wet method, a method of forming by a sol-gel method using a metal alkoxide or the like, a method of applying a resin having a low refractive index such as a fluororesin to form the resin, and a low refractive index particles contained in the resin composition. A method of forming by applying a coating liquid for forming a refractive index layer can be mentioned. Examples of the dry method include a method of selecting particles having a desired refractive index from low refractive index particles described later and forming them by a physical vapor deposition method or a chemical vapor deposition method.
The wet method is superior to the dry method in terms of production efficiency, suppression of oblique reflection hue, and chemical resistance. Further, among the wet methods, from the viewpoint of adhesion, water resistance, scratch resistance and low refractive index, the binder resin composition is formed with a coating liquid for forming a low refractive index layer containing low refractive index particles. Is preferable. In other words, the low refractive index layer preferably contains a binder resin and low refractive index particles.

The low index of refraction layer is usually located on the outermost surface of the optical laminate. Therefore, the low refractive index layer is required to have good scratch resistance, and the general-purpose low refractive index layer is also designed to have a predetermined scratch resistance.
In recent years, hollow particles having a large particle diameter have been used as low-refractive index particles in order to reduce the refractive index of the low-refractive index layer. Even if the surface of the low refractive index layer containing hollow particles having a large particle diameter is rubbed with only fine solids (for example, sand) or only oil, the scratches cannot be visually recognized. , Solid matter and oil content may be attached and scratched by rubbing (hereinafter, the phenomenon may be referred to as "oil dust resistance"). The operation of rubbing with solids and oily substances is, for example, an operation in which the user operates a touch panel type image display device with a finger to which oil content contained in cosmetics and food and sand contained in the atmosphere adheres. Corresponds to.
It is preferable to improve the oil dust resistance of the low refractive index layer in that the effects of the low refractive index layer (antireflection, suppression of rainbow unevenness, etc.) can be maintained for a long period of time. In addition, "rainbow unevenness" means unevenness of the rainbow pattern caused by the birefringent body such as a stretched plastic film disturbing the polarization state of the linearly polarized light passing through the polarizing element.

The above-mentioned scratches tend to occur mainly due to a part of the hollow particles contained in the low refractive index layer being chipped or the hollow particles falling off. It is considered that the cause of this is that the unevenness caused by the hollow particles formed on the surface of the low refractive index layer is large. That is, when the surface of the low refractive index layer is rubbed with a finger to which the solid matter and the oil are attached, the oil becomes a binder and the finger moves on the surface of the low refractive index layer while the solid matter is attached to the finger. At this time, a phenomenon in which a part of solid matter (for example, a pointed portion of sand) enters the concave portion on the surface of the low refractive index layer, and the solid matter entering the concave portion passes through the concave portion together with the finger to form a convex portion (hollow particle). It is thought that the phenomenon of overcoming is likely to occur, and at that time, a large force is applied to the convex portion (hollow particles), so that the hollow particles are damaged or fall off. Further, it is considered that the resin itself located in the recess was also damaged by the friction caused by the solid substance, and the hollow particles were more likely to fall off due to the damage of the resin.
In a preferred embodiment of the low refractive index layer, hollow particles and non-hollow particles are used in combination as low refractive index particles, and the hollow particles and the non-hollow particles are uniformly dispersed to improve the oil dust resistance. It can be done easily.

In order to improve the oil dust resistance, the low refractive index particles preferably contain hollow particles and non-hollow particles.
The material of the hollow particles and the non-hollow particles may be either an inorganic compound such as silica or magnesium fluoride or an organic compound, but silica is preferable from the viewpoint of low refractive index and strength. Hereinafter, hollow silica particles and non-hollow silica particles will be mainly described.

Hollow silica particles refer to particles having an outer shell layer made of silica, the inside of the particles surrounded by the outer shell layer is a cavity, and the inside of the cavity contains air. Hollow silica particles are particles whose refractive index decreases in proportion to the gas occupancy rate as compared with the original refractive index of silica due to the inclusion of air. Non-hollow silica particles are particles that are not hollow inside, such as hollow silica particles. The non-hollow silica particles are, for example, solid silica particles.
The shapes of the hollow silica particles and the non-hollow silica particles are not particularly limited, and may be a true sphere, a spheroidal shape, or a substantially spherical shape such as a polyhedral shape that can be approximated to a sphere. Of these, in consideration of scratch resistance, a true spherical shape, a spheroidal shape, or a substantially spherical shape is preferable.

Since the hollow silica particles contain air inside, they play a role of lowering the refractive index of the entire low refractive index layer. By using hollow silica particles having a large particle diameter with an increased proportion of air, the refractive index of the low refractive index layer can be further reduced. On the other hand, hollow silica particles tend to be inferior in mechanical strength. In particular, when hollow silica particles having a large particle diameter with an increased proportion of air are used, the scratch resistance of the low refractive index layer tends to be lowered.
The non-hollow silica particles play a role of improving the scratch resistance of the low refractive index layer by being dispersed in the binder resin.

In order to uniformly disperse the particles in the resin in the film thickness direction while containing the hollow silica particles and the non-hollow silica particles in the binder resin at a high concentration, the hollow silica particles are close to each other, and the hollow silica particles are further arranged. It is preferable to set the average particle size of the hollow silica particles and the average particle size of the non-hollow silica particles so that the non-hollow particles can enter between the two. Specifically, the ratio of the average particle size of the non-hollow silica particles to the average particle size of the hollow silica particles (average particle size of the non-hollow silica particles / average particle size of the hollow silica particles) may be 0.29 or less. It is preferably 0.20 or less, and more preferably 0.20 or less. Moreover, the ratio of the average particle diameter is preferably 0.05 or more. Considering the optical characteristics and the mechanical strength, the average particle size of the hollow silica particles is preferably 50 nm or more and 100 nm or less, and more preferably 60 nm or more and 80 nm or less. Further, considering the dispersibility while preventing the agglomeration of the non-hollow silica particles, the average particle diameter of the non-hollow silica particles is preferably 5 nm or more and 20 nm or less, and more preferably 10 nm or more and 15 nm or less.

The surface of the hollow silica particles and the non-hollow silica particles is preferably coated with a silane coupling agent. It is more preferable to use a silane coupling agent having a (meth) acryloyl group or an epoxy group.
By surface-treating the silica particles with a silane coupling agent, the affinity between the silica particles and the binder resin is improved, and the aggregation of the silica particles is less likely to occur, so that the dispersion of the silica particles tends to be uniform. A general-purpose silane coupling agent can be used.

As the content of the hollow silica particles increases, the filling rate of the hollow silica particles in the binder resin increases, and the refractive index of the low refractive index layer decreases. Therefore, the content of the hollow silica particles is preferably 100 parts by mass or more, and more preferably 150 parts by mass or more with respect to 100 parts by mass of the binder resin.
On the other hand, if the content of the hollow silica particles in the binder resin is too large, the number of hollow silica particles exposed from the binder resin increases and the amount of the binder resin bonded between the particles decreases. Therefore, the hollow silica particles tend to be easily damaged or fall off, and the mechanical strength such as scratch resistance of the low refractive index layer tends to decrease. Therefore, the content of the hollow silica particles is preferably 400 parts by mass or less, and more preferably 300 parts by mass or less with respect to 100 parts by mass of the binder resin.

If the content of the non-hollow silica particles is low, even if the non-hollow silica particles are present on the surface of the low refractive index layer, they may not affect the increase in hardness. Further, when a large amount of non-hollow silica particles are contained, the influence of shrinkage unevenness due to the polymerization of the binder resin can be reduced, and the unevenness generated on the surface of the low refractive index layer after the resin is cured can be reduced. Therefore, the content of the non-hollow silica particles is preferably 90 parts by mass or more, and more preferably 100 parts by mass or more with respect to 100 parts by mass of the binder resin.
On the other hand, if the content of the non-hollow silica particles is too large, the non-hollow silica tends to aggregate, causing uneven shrinkage of the binder resin and increasing surface irregularities. Therefore, the content of the non-hollow silica particles is preferably 200 parts by mass or less, and more preferably 150 parts by mass or less with respect to 100 parts by mass of the binder resin.

By containing the hollow silica particles and the non-hollow silica particles in the binder resin at the above ratio, the barrier property of the low refractive index layer can be improved. It is presumed that this is because the silica particles are uniformly dispersed at a high filling rate, so that the permeation of gas and the like is hindered.
In addition, various cosmetics such as sunscreens and hand creams may contain low molecular weight polymers with low volatility. By improving the barrier property of the low refractive index layer, it is possible to suppress the penetration of the low molecular weight polymer into the coating film of the low refractive index layer, and the low molecular weight polymer remains in the coating film for a long period of time (for example, appearance). Abnormality) can be suppressed.

The binder resin of the low refractive index layer preferably contains a cured product of the ionizing radiation curable resin composition. As the cured product of the ionizing radiation curable resin composition of the low refractive index layer, a general-purpose material can be used, and examples thereof include the radically polymerizable resin exemplified in the hard coat layer.

Regarding the radically polymerizable compound, the (meth) acrylate-based compound having four or more ethylenically unsaturated bonding groups is referred to as a “polyfunctional (meth) acrylate-based compound”, and the ethylenically unsaturated bonding group is referred to as 2-3. When the (meth) acrylate-based compound having one is defined as a "low-functional (meth) acrylate-based compound", the proportion of the low-functional (meth) acrylate-based compound in the radically polymerizable compound is 60% by mass or more. It is preferably 80% by mass or more, more preferably 90% by mass or more, further preferably 95% by mass or more, and most preferably 100% by mass. The low-functional (meth) acrylate-based compound can suppress uneven shrinkage during curing to facilitate smoothing the uneven shape of the surface of the low-refractive index layer, and can also produce low-refractive index particles (particularly silica particles) in the low-refractive index layer. It is preferable because it is easy to disperse uniformly.
Further, from the viewpoint of suppressing the shrinkage unevenness during curing and facilitating smoothing the uneven shape of the surface of the low refractive index layer, the low functional (meth) acrylate compound has two ethylenically unsaturated bond groups. It is preferably a (meth) acrylate-based compound having.

Further, the radically polymerizable compound forming the low refractive index layer may be a compound in which a part of the molecular skeleton is modified from the viewpoint of suppressing uneven shrinkage due to crosslinking and improving the smoothness of the surface. For example, as the radically polymerizable compound, a (meth) acrylate compound modified with ethylene oxide, propylene oxide, caprolactone, isocyanuric acid, alkyl, cyclic alkyl, aromatic, bisphenol and the like can also be used. In particular, from the viewpoint of enhancing the affinity with low refractive index particles (particularly silica particles) and facilitating uniform dispersion of low refractive index particles (particularly silica particles) in the low refractive index layer, radically polymerizable compounds are used. A (meth) acrylate-based compound modified with an alkylene oxide such as ethylene oxide or propylene oxide is preferable.
The ratio of the alkylene oxide-modified (meth) acrylate compound in the radically polymerizable compound is preferably 60% by mass or more, more preferably 80% by mass or more, still more preferably 90% by mass or more. , 95% by mass or more is more preferable, and 100% by mass is most preferable. The alkylene oxide-modified (meth) acrylate compound is preferably a low-functional (meth) acrylate compound, and more preferably a (meth) acrylate compound having two ethylenically unsaturated bonding groups. ..

The low refractive index layer preferably contains a leveling agent from the viewpoint of antifouling property and surface smoothness.
Examples of the leveling agent include fluorine-based and silicone-based, but silicone-based is preferable. By including the silicone-based leveling agent, the surface of the low reflectance layer can be made smoother. Further, the slipperiness and antifouling property (fingerprint wiping property, large contact angle with pure water and hexadecane) of the surface of the low reflectance layer can be improved.

The content of the leveling agent is preferably 1 to 25 parts by mass, more preferably 2 to 20 parts by mass, and further preferably 5 to 18 parts by mass with respect to 100 parts by mass of the binder resin. .. By setting the content of the leveling agent to 1 part by mass or more, it is possible to easily impart various performances such as antifouling property. Further, by setting the content of the leveling agent to 25 parts by mass or less, it is possible to suppress a decrease in scratch resistance.

From the viewpoint of obtaining excellent surface resistance, the low refractive index layer preferably has a maximum height roughness Rz of 110 nm or less, more preferably 100 nm or less, more preferably 90 nm or less, and more preferably 70 nm or less. It is more preferable that it is 60 nm or less, and it is more preferable that it is 60 nm or less. From the viewpoint of suppressing blocking, Rz is preferably 20 nm or more, and more preferably 30 nm or more.
Further, Rz / Ra (Ra is an arithmetic mean roughness) is preferably 22.0 or less, more preferably 17.0 or less, more preferably 12.0 or less, and 10.0 or less. Is more preferable. Setting Rz / Ra in the above range is particularly effective when Rz is as large as about 90 to 110 nm.

In the present specification, Ra and Rz refer to the roughness of the two-dimensional roughness parameter described in the scanning probe microscope SPM-9600 upgrade kit instruction manual (SPM-9600 February 2016, P.194-195). It is an extension of the dimension. Ra and Rz are defined as follows.

(Arithmetic Mean Roughness Ra)
Only the reference length (L) is extracted from the roughness curve in the direction of the average line, the X axis is taken in the direction of the average line of the extracted portion, and the Y axis is taken in the direction of the vertical magnification, and the roughness curve is set to y = f ( When expressed by x), it can be obtained by the following equation.

(Maximum height roughness Rz)
A value obtained by extracting the reference length from the roughness curve in the direction of the average line and measuring the distance between the peak line and the valley bottom line of the extracted portion in the direction of the vertical magnification of the roughness curve.

A small Rz means that the convex portion due to the hollow silica particles in the minute region is small. Further, the fact that Rz / Ra is small means that the unevenness caused by the silica particles in the minute region is uniform and does not have the unevenness protruding with respect to the average elevation difference of the unevenness. In the present invention, the value of Ra is not particularly limited, but Ra is preferably 15 nm or less, more preferably 12 nm or less, further preferably 10 nm or less, and preferably 6.5 nm or less. Even more preferable.
By uniformly dispersing the low refractive index particles in the low refractive index layer and suppressing the shrinkage unevenness of the low refractive index layer, it becomes easy to satisfy the above ranges of Rz and Rz / Ra.

When Rz and Rz / Ra on the surface of the low refractive index layer are in the above range, the resistance when the solid material gets over the convex portion on the surface of the low refractive index layer (due to the hollow silica particles existing near the surface) is reduced. be able to. Therefore, it is considered that the solid matter moves smoothly on the surface of the low refractive index layer even if it is rubbed with sand containing oil while applying a load. It is also considered that the hardness of the recess itself has increased. As a result, it can be inferred that the hollow silica particles were prevented from being damaged or dropped off, and the binder resin itself was also prevented from being damaged.

The surface roughness of Rz, Ra, etc. means the average value of the measured values of 14 points excluding the minimum value and the maximum value of the measured values of 16 points unless otherwise specified.
In the present specification, the above 16 measurement points are obtained when a region 0.5 cm from the outer edge of the measurement sample is set as a margin and a line that divides the vertical direction and the horizontal direction into five equal parts is drawn with respect to the region inside the margin. It is preferable to set 16 points of intersection as the center of measurement. The measurement sample is preferably 5 cm × 5 cm.

The low refractive index layer can be formed by applying and drying a low refractive index layer forming coating liquid obtained by dissolving or dispersing each component constituting the low refractive index layer. Usually, a solvent is used in the coating liquid to adjust the viscosity and to dissolve or disperse each component.
Examples of the solvent include ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, etc.), ethers (dioxane, tetrahydrofuran, etc.), aliphatic hydrocarbons (hexane, etc.), alicyclic hydrocarbons (cyclohexane, etc.), and the like. Aromatic hydrocarbons (toluene, xylene, etc.), carbon halides (dichloromethane, dichloroethane, etc.), esters (methyl acetate, ethyl acetate, butyl acetate, etc.), alcohols (butanol, cyclohexanol, etc.), cellosolves (butanol, cyclohexanol, etc.) Methyl cellosolve, ethyl cellosolve, etc.), cellosolve acetates, sulfoxides (dimethylsulfoxide, etc.), glycol ethers (1-methoxy-2-propylacetate, etc.), amides (dimethylformamide, dimethylacetamide, etc.), etc. can be exemplified. It may be a mixture of these.

If the solvent volatilizes too quickly, the solvent will convection violently when the coating liquid for forming a low refractive index layer is dried. Therefore, even if the silica particles in the coating liquid are in a uniformly dispersed state, the uniformly dispersed state is likely to collapse due to the intense convection of the solvent during drying. Therefore, it is preferable that the solvent contains a solvent having a slow evaporation rate. Specifically, it is preferable to contain a solvent having a relative evaporation rate (relative evaporation rate when the evaporation rate of n-butyl acetate is 100) of 70 or less, and more preferably 30 to 60. The solvent having a relative evaporation rate of 70 or less is preferably 10 to 50% by mass, preferably 20 to 40% by mass, based on the total solvent.
Examples of the relative evaporation rate of the solvent having a slow evaporation rate are 64 for isobutyl alcohol, 47 for 1-butanol, 44 for 1-methoxy-2-propyl acetate, 38 for ethyl cellosolve, and 32 for cyclohexanone.
It is preferable that the residual amount of the solvent (solvent other than the solvent having a slow evaporation rate) has excellent solubility of the resin. Further, the residual amount of the solvent preferably has a relative evaporation rate of 100 or more.

Further, in order to suppress the convection of the solvent during drying and improve the dispersibility of the silica particles, it is preferable that the drying temperature at the time of forming the low refractive index layer is as low as possible. The drying temperature can be appropriately set in consideration of the type of solvent, the dispersibility of silica particles, the production rate, and the like.

-High refractive index layer-
The high refractive index layer is formed on the hard coat layer side of the low refractive index layer as needed.

The high refractive index layer preferably has a refractive index of 1.53 to 1.85, more preferably 1.54 to 1.80, more preferably 1.55 to 1.75, and more preferably 1.56 to 1.70. preferable.
The thickness of the high refractive index layer is preferably 200 nm or less, more preferably 50 to 180 nm, and even more preferably 70 to 150 nm.

The high refractive index layer can be formed from, for example, a coating liquid for forming a high refractive index layer containing a binder resin composition and high refractive index particles. In other words, the high refractive index layer contains, for example, a binder resin and high refractive index particles.

The binder resin of the high refractive index layer preferably contains a cured product of the ionizing radiation curable resin composition. As the cured product of the ionizing radiation curable resin composition of the high refractive index layer, a general-purpose material can be used, and examples thereof include the radical polymerizable resin exemplified in the hard coat layer.

Examples of the high refractive index particles include antimony pentoxide (1.79), zinc oxide (1.90), titanium oxide (2.3 to 2.7), cerium oxide (1.95), and tin-doped indium oxide (1. 95 to 2.00), antimony-doped tin oxide (1.75 to 1.85), yttrium oxide (1.87), zirconium oxide (2.10) and the like.

The average particle size of the high-refractive index particles is preferably 2 nm or more, more preferably 5 nm or more, still more preferably 10 nm or more. The average particle size of the high-refractive index particles is preferably 200 nm or less, more preferably 100 nm or less, more preferably 80 nm or less, more preferably 60 nm or less, and even more preferably 30 nm or less, from the viewpoint of suppressing whitening and transparency. The smaller the average particle diameter of the high-refractive index particles, the better the transparency, and in particular, the transparency can be extremely improved by setting the particle diameter to 60 nm or less.

The average particle diameter of the high-refractive index particles or the low-refractive index particles can be calculated by the following operations (y1) to (y3).
(Y1) The cross section of the high refractive index layer or the low refractive index layer is imaged by TEM or STEM. The acceleration voltage of TEM or STEM is preferably 10 kv to 30 kV, and the magnification is preferably 50,000 to 300,000 times.
(Y2) Arbitrary 10 particles are extracted from the observation image, and the particle diameter of each particle is calculated. The particle size is measured as the distance between straight lines in a combination of two straight lines such that the distance between the two straight lines is maximized when the cross section of the particle is sandwiched between two arbitrary parallel straight lines. When the particles are agglomerated, the agglomerated particles are regarded as one particle and measured.
(Y3) The same operation is performed 5 times in the observation image on another screen of the same sample, and the value obtained from the number average of the particle diameters for a total of 50 particles is the average particle diameter of the high-refractive index particles or the low-refractive index particles. And.

The antireflection layer such as the low refractive index layer and the high refractive index layer may contain an ultraviolet absorber as described above.
Further, the antireflection layer may contain various additives as long as the effect of the present invention is not impaired. Examples of the additive include a light stabilizer, an antioxidant, an antifouling agent, an antistatic agent, a leveling agent and the like.

《Adhesive layer》
The optical laminate of the first embodiment may have an adhesive layer on the side opposite to the hard coat layer of the base material layer from the viewpoint of bonding to a polarizing element, a display element, or the like.

Hereinafter, the adhesive layer will be described in common with the first and second embodiments unless otherwise specified.

The adhesive layer may be a pressure-sensitive adhesive layer (so-called “adhesive layer”) or a heat-sensitive adhesive layer (so-called “heat seal layer”), but a pressure-sensitive adhesive layer (adhesive layer) is preferable. ..
The adhesive layer can be formed of a general-purpose resin such as an acrylic resin, a urethane resin, a silicone resin, a melamine resin, an amide resin, an imide resin, and a carbonate resin.

The adhesive layer is preferably a so-called transparent optical adhesive layer (OCA) from the viewpoint of optical characteristics. The transparent optical adhesive layer is preferably made of an acrylic resin from the viewpoint of optical properties, light resistance, weather resistance, heat resistance and transparency.

The adhesive layer preferably contains substantially no dye from the viewpoint of facilitating the maintenance of the adhesive force over time. The term "substantially free" means that the total solid content of the adhesive layer is 0.1% by mass or less, preferably 0.01% by mass or less, and more preferably 0.001% by mass or less.
It can be confirmed, for example, by measuring the infrared absorption spectrum (IR spectrum) that the adhesive layer contains substantially no dye.

The thickness of the adhesive layer is preferably 1 to 100 μm, more preferably 5 to 50 μm.

<Physical characteristics>
The optical laminates of the first and second embodiments preferably have an absorption peak wavelength in a predetermined wavelength range.
For example, the optical laminates of the first and second embodiments have a wavelength of 470 to 510 nm (hereinafter, may be referred to as “wavelength range A”) and a wavelength of 570 to 650 nm (hereinafter, “wavelength range”). It may be referred to as "B")), and it is preferable to have an absorption peak wavelength, and it is more preferable to have an absorption peak wavelength in both the wavelength region A and the wavelength region B. With this configuration, it is possible to easily increase the color purity of the image display device.
The absorption peak wavelength may be provided in a wavelength region other than the wavelength region A and the wavelength region B as long as the effect of the present invention is not impaired.

In the optical laminates of the first embodiment and the second embodiment, the spectral transmittance of the absorption peak wavelength in the wavelength region A is preferably 15% or less, and preferably 10% or less. Further, in the optical laminate, the spectral transmittance of the absorption peak wavelength in the wavelength region B is preferably 15% or less, and preferably 10% or less.

When the optical laminates of the first embodiment and the second embodiment have an absorption peak wavelength between the wavelengths of 470 and 510 nm (wavelength range A), the transmitted light of the optical laminate is L ^* a ^* b ^* color system a. The ^* value and b ^* value are preferably a ^* value of -15.0 to 5.0, more preferably -13.0 to 3.0, and b ^* value of -15.0 to 5.0, preferably -13.0 to -13.0 to 3.0. It is more preferably 3.0.
Further, when the optical laminates of the first and second embodiments have an absorption peak wavelength between 570 and 650 nm (wavelength range B), the L ^* a ^* b ^* color system of the transmitted light of the optical laminate The a ^* value and the b ^* value of are preferably a ^* value of -15.0 to 5.0, more preferably -13.0 to 3.0, and b ^* value of -15.0 to 5.0. It is more preferably 13.0 to 3.0.
Further, when the optical laminates of the first and second embodiments have absorption peak wavelengths in the wavelength region A and the wavelength region B, the L ^* a ^* b ^* color system a ^* value of the transmitted light of the optical laminate is obtained. And b ^* values are preferably a ^* values of -15.0 to 5.0, more preferably -13.0 to 3.0, b ^* values of -15.0 to 5.0, and -13.0 to 3.0. It is more preferable to have.
In the present specification, the L ^* a ^* b ^* color system is based on the L ^* a ^* b ^* color system standardized by the International Commission on Illumination (CIE) in 1976, and is based on JIS Z8781-4. : Adopted in 2013.

From the viewpoint of enhancing the color purity of the image display device, the optical laminates of the first and second embodiments have a wavelength width A of 150% and a wavelength width A of 150 nm or less, which is represented by the following formula (i). It is more preferably 100 nm or less, further preferably 75 nm or less, and even more preferably 50 nm or less. If the wavelength width A is too narrow, the wavelength cut function is insufficient. Therefore, the wavelength width A is preferably 5 nm or more, and more preferably 10 nm or more. In the case of FIG. 6, the wavelength width represented by the reference numeral a corresponds to the wavelength width A of the following formula (i).
<Wavelength width A with 50% spectral transmittance>
[The smallest wavelength that is larger than the absorption peak wavelength of wavelength region A and has a spectral transmittance of 50% or less]-[The wavelength is smaller than the absorption peak wavelength of wavelength region A and the spectral transmittance is Largest wavelength indicating 50% or less] (i)

From the viewpoint of enhancing the color purity of the image display device, the optical laminates of the first and second embodiments have a wavelength width B of 50% spectral transmittance of 150 nm or less, which is represented by the following formula (ii). It is preferably 100 nm or less, and more preferably 100 nm or less. If the wavelength width B is too narrow, the wavelength cut function is insufficient. Therefore, the wavelength width B is preferably 5 nm or more, and more preferably 10 nm or more. In the case of FIG. 6, the wavelength width represented by the reference numeral b corresponds to the wavelength width A of the following equation (ii).
<Wavelength width B with 50% spectral transmittance>
[The smallest wavelength that is larger than the absorption peak wavelength of wavelength region B and has a spectral transmittance of 50% or less]-[The wavelength that is smaller than the absorption peak wavelength of wavelength region B and has a spectral transmittance of 50% or less] Largest wavelength indicating 50% or less] (ii)

The optical laminates of the first and second embodiments have an average spectral transmittance at a wavelength of 460 to 495 nm (blue wavelength range), an average spectral transmittance at a wavelength of 500 to 550 nm (green wavelength range), and a wavelength of 620 to 620. The average spectral transmittance at 700 nm (red wavelength region) is preferably 70% or more, and more preferably 80% or more.

In the optical laminates of the first embodiment and the second embodiment, the total light transmittance of JIS K7361-1: 1997 is preferably 50% or more, more preferably 60% or more, and more preferably 70% or more. Is even more preferable.
In this specification, the light incident surface on the optical laminate when measuring the total light transmittance and the haze described later is the side opposite to the side having the hard coat layer with respect to the base material layer. ..

The optical laminates of the first and second embodiments preferably have a haze of JIS K7136: 2000 of 0.1 to 10%, more preferably 0.1 to 7%, and 0.1 to 5%. % Is more preferable.

In the first and second embodiments, it is preferable that the surface shape of the optical laminate on the side having the hard coat layer is substantially smooth with respect to the base material layer. Approximately smooth means that the arithmetic mean roughness of JIS B0601: 2001 when the cutoff value is 0.8 mm is 0.05 μm or less, preferably 0.03 μm or less, and more preferably 0.01 μm. It is as follows.

In the present specification, the above-mentioned physical properties mean the average value of the measured values at 14 points excluding the minimum value and the maximum value of the measured values at 16 points.
In the present specification, the 16 measurement points are intersections when a region 1 cm from the outer edge of the measurement sample is set as a margin and a line is drawn that divides the vertical direction and the horizontal direction into five equal parts with respect to the region inside the margin. It is preferable to set 16 points of the above as the center of measurement. For example, when the measurement sample is a quadrangle, the measurement is performed centering on 16 points of the intersections of the dotted lines obtained by dividing the area inside the quadrangle into five equal parts in the vertical and horizontal directions, with the area 1 cm from the outer edge of the quadrangle as the margin. , It is preferable to calculate the parameter with the average value. When the measurement sample has a shape other than a quadrangle such as a circle, an ellipse, a triangle, or a pentagon, it is preferable to draw a quadrangle inscribed in these shapes and measure 16 points of the quadrangle by the above method.

<Specific example of layer structure>
The following A1 to A20 are examples of the layer structure of the optical laminate of the first embodiment.
In the following A1 to A20, the outer layer side is on the left side, and "/" indicates the interface of the layer. Further, as a layer structure of the optical laminate of the first embodiment, a layer structure having an adhesive layer on the inner layer side of the following A1 to A20 can be mentioned. Further, in the following A11, A12, A16 and A17, the hard coat layer does not contain an ultraviolet absorber, and the resin layer 1 contains an ultraviolet absorber.

A1: Hard coat layer / base material layer containing an ultraviolet absorber (containing a dye that penetrates from the hard coat layer side)
A2: Hard coat layer / base material layer containing an ultraviolet absorber (containing a dye that penetrates from the opposite side of the hard coat layer)
A3: Hardcoat layer / Base material layer containing UV absorber (contains dye that penetrates from the hardcoat layer side)
A4: Hardcoat layer / Base material layer containing UV absorber (contains dye that penetrates from the opposite side of the hardcoat layer)
A5: Hardcoat layer / base material layer (contains a dye that penetrates from the opposite side of the hardcoat layer and contains an ultraviolet absorber that penetrates from the hardcoat layer side)
A6: Anti-reflection layer / hard coat layer containing UV absorber / base material layer (containing dye that penetrates from the hard coat layer side)
A7: Anti-reflection layer / hard coat layer containing UV absorber / base material layer (containing dye that penetrates from the opposite side of the hard coat layer)
A8: Anti-reflection layer / hard coat layer / base material layer containing an ultraviolet absorber (containing a dye that penetrates from the hard coat layer side)
A9: Anti-reflection layer / hard coat layer / base material layer containing an ultraviolet absorber (containing a dye that penetrates from the opposite side of the hard coat layer)
A10: Anti-reflection layer / hard coat layer / base material layer (contains a dye that penetrates from the side opposite to the hard coat layer and contains an ultraviolet absorber that penetrates from the hard coat layer side)
A11: Hardcoat layer / resin layer 1 / base material layer containing UV absorber (containing dye that penetrates from the hardcoat layer side)
A12: Hardcoat layer / resin layer 1 / base material layer containing UV absorber (containing dye that penetrates from the opposite side of the hardcoat layer)
A13: Hardcoat layer / Resin layer 1 / Base material layer containing UV absorber (contains dye that penetrates from the hardcoat layer side)
A14: Hardcoat layer / Resin layer 1 / Base material layer containing UV absorber (contains dye that penetrates from the opposite side of the hardcoat layer)
A15: Hardcoat layer / resin layer 1 / base material layer (contains a dye that penetrates from the opposite side of the hardcoat layer and contains an ultraviolet absorber that penetrates from the hardcoat layer side)
A16: Antireflection layer / Hardcoat layer containing UV absorber / Resin layer 1 / Base material layer (contains dye that penetrates from the hardcoat layer side)
A17: Antireflection layer / Hardcoat layer containing UV absorber / Resin layer 1 / Base material layer (contains dye that penetrates from the opposite side of the hardcoat layer)
A18: Antireflection layer / hard coat layer / resin layer 1 / base material layer containing an ultraviolet absorber (containing a dye that penetrates from the hard coat layer side)
A19: Anti-reflection layer / hard coat layer / resin layer 1 / base material layer containing an ultraviolet absorber (containing a dye that penetrates from the opposite side of the hard coat layer)
A20: Anti-reflection layer / hard coat layer / resin layer 1 / base material layer (an ultraviolet absorber that contains a dye that penetrates from the opposite side of the hard coat layer and that penetrates from the hard coat layer side). Contains)

<Size, shape, etc.>
The optical laminates of the first and second embodiments may be in the form of a single leaf cut to a predetermined size, or in the form of a roll obtained by winding a long sheet into a roll. The size of the single leaf is not particularly limited, but the maximum diameter is about 2 to 500 inches. The "maximum diameter" means the maximum length when any two points of the optical laminate are connected. For example, when the optical laminate is rectangular, the diagonal of the region is the maximum diameter. When the optical laminate is circular, the diameter is the maximum. The optical laminate of the present invention is preferable in that when the maximum diameter is 1000 mm or more, more remarkable effects can be exhibited from the viewpoint of design such as harmony with the surrounding interior. It is more preferable that the maximum diameter of the optical laminate is 1300 mm or more.
The width and length of the roll are not particularly limited, but generally, the width is 500 to 3000 mm and the length is about 500 to 5000 m. The roll-shaped optical laminate can be cut into a single-wafer shape according to the size of an image display device or the like and used. When cutting, it is preferable to exclude the end of the roll whose physical characteristics are not stable.
Further, the shape of the single leaf is not particularly limited, and may be, for example, a polygon (triangle, quadrangle, pentagon, etc.), a circle, or a random irregular shape. More specifically, when the optical laminate has a rectangular shape, the aspect ratio is not particularly limited as long as there is no problem in the display screen. For example, horizontal: vertical = 1: 1, 4: 3, 16:10, 16: 9, 2: 1 and the like can be mentioned, but the aspect ratio is limited to such an aspect ratio in in-vehicle applications and digital signage with rich design. Not done.

<Use>
The optical laminate of the first embodiment and the optical laminate of the second embodiment described later may be suitably used as members constituting an image display device such as an organic EL display device, a liquid crystal display device, and a micro LED display device. can. Examples of the image display device include a television, a PC monitor, a portable information terminal, a wearable information terminal, and VR goggles. Further, the optical laminate of the first embodiment and the optical laminate of the second embodiment described later can be used by being bonded to a plate having light transmittance, a molded body, or the like. Examples of the plate and the molded body having light transmission include a show window, a showcase, a face shield, and a shielding plate.

-Optical laminate of Embodiment 2-
The optical laminate of the second embodiment has a hard coat layer and a base material layer in this order from the outer layer side, and has the configuration of the following (2).
(2) The optical laminate has a resin layer 2 having a thickness of 5.0 μm or less containing a dye 2 and a binder resin as a layer other than the hard coat layer and the base material layer, and the binder resin is a non-radical polymerizable resin. Is. Further, at least one layer selected from the resin layer 2 and the layer located on the outer layer side of the resin layer 2 contains an ultraviolet absorber.

In the second embodiment, the resin layer 2 having a thickness of 5.0 μm or less containing the dye 2 and the binder resin is provided as a layer other than the hard coat layer and the base material layer, and the binder resin is a non-radical polymerizable resin. It takes that.
When the binder resin of the resin layer 2 is a radically polymerizable resin, the dye 2 is deteriorated by the radicals generated from the radically polymerizable resin over time.
Further, when the thickness of the resin layer 2 exceeds 5.0 μm, the surface hardness of the optical laminate becomes insufficient, and the scratch resistance of the optical laminate cannot be improved.

Further, in the second embodiment, it is necessary to include the ultraviolet absorber in at least one layer selected from the resin layer 2 and the layer located on the outer layer side of the resin layer 2. Without this configuration, the dye 2 in the resin layer 2 deteriorates over time.

3 to 4 are cross-sectional views showing an embodiment of the optical laminate (100) of the second embodiment.
The optical laminate (100) of FIGS. 3 to 4 has a hard coat layer (30) and a base material layer (10) in this order from the outer layer side.
Further, the optical laminate (100) of FIGS. 3 to 4 has a resin layer 2 (22) containing the dye 2 (82) as a layer other than the hard coat layer (30) and the base material layer (10). There is.
Further, the optical laminate (100) of FIG. 3 contains an ultraviolet absorber (70) in the base material layer (10) located on the outer layer side of the resin layer 2. Further, the optical laminate (100) of FIG. 4 contains an ultraviolet absorber (70) in the hard coat layer (30) located on the outer layer side of the resin layer 2. Further, the optical laminate (100) of FIG. 4 has a resin layer 1 (21) between the hard coat layer (30) and the resin layer 2 (22).
The optical laminate of the second embodiment is not limited to the configurations shown in FIGS. 1 and 2. For example, the optical laminate of the second embodiment may contain an ultraviolet absorber (70) in the hard coat layer (30) in the configuration of FIG. Further, in the configuration of FIG. 4, the optical laminate of the second embodiment may have a configuration in which the hard coat layer (30) and the resin layer 2 (22) are in contact with each other without having the resin layer 1 (21). .. Further, the optical laminated body of the second embodiment may have a laminated structure different from the laminated structure of FIGS. 3 to 4.

<Resin layer 2>
The resin layer 2 is a layer having a thickness of 5.0 μm or less and containing the dye 2 and the binder resin. The binder resin of the resin layer 2 is a non-radical polymerizable resin.

The resin layer 2 is preferably located on the inner layer side of the hard coat layer from the viewpoint of improving the scratch resistance of the optical laminate (FIGS. 3 and 4), and is opposite to the hard coat layer of the base material layer. It is more preferably located on the side (Fig. 4).

<< Dye 2 >>
Examples of the dye 2 contained in the resin layer 2 of the second embodiment include dyes 2 similar to the dyes exemplified in the first embodiment (for example, organic dyes such as porphyrin-based and squarylium-based dyes). Of these, porphyrin-based organic dyes are preferable, and tetraazaporphyrin-based organic dyes are more preferable.

The dye 2 of the second embodiment may be an encapsulated dye in which the dye is encapsulated in a translucent film. By using the encapsulating dye as the dye 2, deterioration of the dye 2 can be more easily suppressed. Further, the encapsulating dye is preferable because it can be expected to have an antiglare effect by imparting an uneven shape to the surface of the optical laminate.

The translucent film of the encapsulating dye is preferably an inorganic oxide such as silica and alumina, and more preferably silica.
The film of the inorganic oxide is preferable in that it easily absorbs ultraviolet rays, and further, it is preferable in that it can impart internal scattering property due to the difference in refractive index from the binder resin.

The average particle size of the encapsulating dye is preferably 0.01 to 5 μm. From the viewpoint of imparting the above-mentioned antiglare property or internal scattering property, the average particle size of the encapsulating dye is preferably 0.5 to 5 μm.

The content of the dye is preferably 0.001 to 0.500 g / m ² and more preferably 0.001 to 0.150 g / m ² in terms of the unit area of the optical laminate. ..

In the second embodiment, the content of the dye 2 varies depending on the thickness of the resin layer 2, and therefore cannot be unconditionally determined. However, it is preferably 0.01 to 10 parts by mass with respect to 100 parts by mass of the binder resin. It is more preferably 05 to 5 parts by mass.

In the second embodiment, the dye preferably has a molecular weight of more than 400, more preferably more than 1,000, from the viewpoint of facilitating the suppression of bleeding from the resin layer 2. The upper limit of the molecular weight of the dye 2 is not particularly limited, but is usually 2000 or less.

《Binder resin》
The binder resin of the resin layer 2 of the second embodiment needs to be a non-radical polymerizable resin.
The non-radical polymerizable resin preferably contains at least one selected from a cured product of a thermoplastic resin and a thermosetting resin composition. Among these, a thermoplastic resin is preferable from the viewpoint of adhesion to the base material layer, the hard coat layer and the like.

Examples of the thermoplastic resin as the non-radical polymerizable resin include acrylic resin, cellulose resin, urethane resin, vinyl chloride resin, polyester resin, polyolefin resin, polycarbonate, nylon, polystyrene, ABS resin and the like. .. Among these, an acrylic resin is preferable, and among the acrylic resins, polymethylmethacrylate (PMMA) is preferable.
Further, the thermoplastic resin preferably has a polystyrene-equivalent weight average molecular weight measured by the GPC method of 5,000 to 5 million, more preferably 10,000 to 1 million.

The cured product of the thermosetting resin composition as a non-radical polymerizable resin is a cured product of the composition containing the thermosetting resin. Examples of the thermosetting resin include acrylic resin, urethane resin, phenol resin, urea melamine resin, epoxy resin, unsaturated polyester resin, silicone resin and the like. To the thermosetting resin composition, a curing agent such as an isocyanate-based curing agent is added to these curable resins, if necessary.

《Thickness》
The thickness of the resin layer 2 needs to be 5.0 μm or less.
As described above, when the thickness of the resin layer 2 exceeds 5.0 μm, the surface hardness of the optical laminate becomes insufficient, and the scratch resistance of the optical laminate cannot be improved. The thickness of the resin layer 2 is preferably 4.5 μm or less, and more preferably 4.0 μm or less.
If the thickness of the resin layer 2 is too thin, it becomes difficult for the dye to exert its action. Therefore, the thickness of the resin layer 2 is preferably 1.0 μm or more, and more preferably 1.5 μm or more.

The resin layer 2 may contain an ultraviolet absorber.
Further, the resin layer 2 may contain various additives as long as the effects of the present invention are not impaired. Examples of the additive include a light stabilizer, an antioxidant, a refractive index adjusting agent, an antiglare agent, an antifouling agent, an antistatic agent, a leveling agent and the like.

The resin layer 2 is preferably not a so-called "adhesive layer". When the adhesive layer contains a dye, the adhesive strength may decrease over time, causing problems such as peeling in the image display device.
In this specification, in the tilting ball tack test of JIS Z0237: 2009, the ball does not stop in the measuring unit for 5 seconds or more under the conditions of "ball number: No. 1" and "tilt angle: 20 °". Is regarded as a "layer that does not correspond to an adhesive layer".

<Layer containing UV absorber>
The optical laminate of the second embodiment requires that the ultraviolet absorber is contained in at least one layer selected from the resin layer 2 and the layer located on the outer layer side of the resin layer 2.

In the second embodiment, the ultraviolet absorber may be contained only in the resin layer 2, or the ultraviolet absorber may be contained only in the layer located on the outer layer side of the resin layer 2, and both of them may contain the ultraviolet absorber. May include.
From the viewpoint of further suppressing the deterioration of the dye, it is preferable that the layer located on the outer layer side of the resin layer 2 contains an ultraviolet absorber. Examples of the layer located on the outer layer side of the resin layer 2 include a base material layer, a hard coat layer, a resin layer 1, and an antireflection layer.

Examples of the ultraviolet absorber of the second embodiment include the same as those exemplified in the first embodiment.
The suitable content of the ultraviolet absorber when the layer containing the ultraviolet absorber is the base material layer is as exemplified in the first embodiment. Further, the suitable content of the ultraviolet absorber when the layer containing the ultraviolet absorber is a hard coat layer is as exemplified in the first embodiment.
In the second embodiment, when the ultraviolet absorber is contained in the resin layer 2, the content of the ultraviolet absorber is preferably 0.01 to 30 parts by mass with respect to 100 parts by mass of the binder resin of the resin layer 2, preferably 0.01. Up to 15 parts by mass is more preferable, and 0.5 to 10 parts by mass is even more preferable.

<Base layer>
In the second embodiment, the base material layer includes a plastic film and glass.
Examples of the plastic film include those exemplified in the first embodiment, and among them, an acrylic film or a triacetyl cellulose film is preferable. When a plastic film is used as the base material layer of the second embodiment, the plastic film may contain a penetrating dye.
Examples of the glass include soda-lime glass, borosilicate glass, quartz glass and the like.

When the base material layer contains an ultraviolet absorber, as described above, the ultraviolet absorber may be one that has penetrated into the base material layer.

In the second embodiment, when the base material layer is a plastic film, the lower limit is preferably 3 μm or more, more preferably 10 μm or more, still more preferably 20 μm or more, and the upper limit is preferably 300 μm or less, more preferably 20 μm or less. It is more preferably 100 μm or less, still more preferably 70 μm or less, still more preferably 45 μm or less, still more preferably 30 μm or less.
Further, in the second embodiment, when the base material layer is glass, the thickness is preferably 0.01 to 5 mm, more preferably 0.02 to 3 mm, and more preferably 0.03 to 1 mm. More preferred.

<Hard coat layer>
The embodiment of the hard coat layer of the second embodiment is as described above.

<Other layers>
The optical laminate of the second embodiment may have a layer (other layers) other than the base material layer, the hard coat layer and the resin layer 2. Examples of other layers include a resin layer 1, an antireflection layer, and an adhesive layer.
The embodiments of the resin layer 1 and the antireflection layer of the second embodiment are as described above.

《Adhesive layer》
The optical laminate of the second embodiment may have an adhesive layer on the side opposite to the hard coat layer of the base material layer from the viewpoint of bonding to a polarizing element, a display element, or the like. When the resin layer 2 is further provided on the side opposite to the hard coat layer of the base material layer, it is preferable that the hard coat layer, the base material layer, the resin layer 2, and the adhesive layer are in this order from the outer layer side.

The embodiment of the adhesive layer of the second embodiment is as described above.

<Specific example of layer structure>
The following B1 to B10 are examples of the layer structure of the optical laminate of the second embodiment.
In the following B1 to B10, the outer layer side is on the left side, and "/" indicates the interface of the layer. Further, as a layer structure of the optical laminate of the second embodiment, there is also a layer structure having an adhesive layer on the inner layer side of the following B1 to B10.

B1: Hard coat layer / Base material layer containing UV absorber / Resin layer 2
B2: Hard coat layer / resin layer 2 / base material layer 2 containing an ultraviolet absorber / base material layer B3: hard coat layer / base material layer (containing an ultraviolet absorber that penetrates from the hard coat layer side or the side opposite to the hard coat layer) ) / Resin layer 2
B4: Antireflection layer / Hardcoat layer / Base material layer containing UV absorber / Resin layer 2
B5: Antireflection layer / Hardcoat layer containing UV absorber / Resin layer 2 / Base material layer B6: Antireflection layer / Hardcoat layer / Base material layer (permeation from the hardcoat layer side or the side opposite to the hardcoat layer) (Contains UV absorber) / Resin layer 2
B7: Hard coat layer containing UV absorber / Resin layer 1 / Resin layer 2 / Base material layer B8: Antireflection layer / Hard coat layer containing UV absorber / Resin layer 1 / Resin layer 2 / Base material layer B9: Hard coat layer / Resin layer containing UV absorber 1 / Resin layer 2 / Base material layer B10: Antireflection layer / Hard coat layer / Resin layer containing UV absorber 1 / Resin layer 2 / Base material layer

[Polarizer]
The polarizing plate of the present invention has a polarizing element, a transparent protective plate A arranged on one side of the polarizing element, and a transparent protective plate B arranged on the other side of the polarizing element. At least one of the transparent protective plate A and the transparent protective plate B is the above-mentioned optical laminate of the present invention, and the optical laminate is such that the surface on the hard coat layer side faces the opposite side to the polarizing element. It is formed by laminating an optical laminate of the present invention on which a body is arranged and another optical member.

<Polarizer>
Examples of the splitter include sheet-type splitters such as a polyvinyl alcohol film dyed and stretched with iodine, a polyvinyl formal film, a polyvinyl acetal film, and an ethylene-vinyl acetate copolymerization system saponified film, and a large number arranged in parallel. Examples thereof include a wire grid type polarizing element made of the metal wire of the above, a lyotropic liquid crystal, a coated type polarizing element coated with a bicolor guest-host material, and a multilayer thin film type polarizing element. It should be noted that these splitters may be reflective modulators having a function of reflecting a polarizing component that does not transmit.

<Transparent protective plate>
A transparent protective plate A is arranged on one side of the polarizing element, and a transparent protective plate B is arranged on the other side.
Examples of the transparent protective plate A and the transparent protective plate B include a plastic film and glass. Examples of the plastic film include a polyester film, a polycarbonate film, a cycloolefin polymer film and an acrylic film, and these stretched films are preferable from the viewpoint of mechanical strength. Examples of the glass include alkaline glass, nitrided glass, soda-lime glass, borosilicate glass, lead glass and the like. Further, it is preferable that the glass as a transparent protective plate for protecting the polarizing element is also used as another member of the image display device. For example, it is preferable to use both the glass substrate of the liquid crystal display element and the transparent protective plate that protects the polarizing element.
It is preferable that the polarizing element and the transparent protective plate are bonded to each other via an adhesive. As the adhesive, a general-purpose adhesive can be used, and a PVA-based adhesive is preferable.

In the polarizing plate of the present invention, both the transparent protective plate A and the transparent protective plate B may be the above-mentioned optical laminate of the present invention, but one of the transparent protective plate A and the transparent protective plate B of the present invention described above. It is preferably an optical laminate of. Further, it is preferable that the transparent protective plate on the light emitting surface side of the polarizing element is the above-mentioned optical laminate of the present invention.

[Image display device]
The image display device 120 of the present invention has a display element 110 and the above-mentioned optical laminate 100 of the present invention or the above-mentioned polarizing plate of the present invention (FIG. 5).

The optical laminate 100 or the polarizing plate is usually arranged on the light emitting surface side of the display element 110 as shown in FIG. When the display element has light transmittance, the optical laminate 100 or the polarizing plate may be arranged on the side opposite to the light emitting surface of the display element. For example, when the display element is a liquid crystal display element, an optical laminate or a polarizing plate may be arranged between the liquid crystal display element and the backlight.

Examples of the display element include a liquid crystal display element, an EL display element (organic EL display element, an inorganic EL display element), a plasma display element, and the like, and further, an LED display element such as a micro LED display element can be mentioned. These display elements may have a touch panel function inside the display element.
Examples of the liquid crystal display method of the liquid crystal display element include an IPS method, a VA method, a multi-domain method, an OCB method, an STN method, and a TSTN method. If the display element is a liquid crystal display element, a backlight is required. The backlight is arranged on the side opposite to the light emitting surface of the liquid crystal display element.

Further, the image display device of the present invention may be an image display device with an on-cell type or out-cell type touch panel. In the case of an image display device with a touch panel, the optical laminate of the present invention may be incorporated into a component of the touch panel.

Next, the present invention will be described in more detail by way of examples, but the present invention is not limited to these examples. In addition, "part" and "%" are based on mass unless otherwise specified.

1. 1. Measurement and evaluation The optical laminates of Examples and Comparative Examples were measured and evaluated as follows. Unless otherwise specified, the atmosphere at the time of each measurement and evaluation was a temperature of 23 ± 5 ° C. and a humidity of 40 to 65%. Further, before the start of each measurement and evaluation, the target sample was exposed to the atmosphere for 30 minutes or more, and then the measurement and evaluation were performed. The results are shown in Table 1.

1-1. Deterioration of Dye Samples were prepared by cutting the optical laminates of Examples and Comparative Examples into 10 cm squares. The cutting points were selected from random parts after visually confirming that there were no abnormal points such as dust and scratches. A spectrophotometer (manufactured by Shimadzu Corporation, trade name: UV-2450) was used to measure the spectral transmittance of the sample before the durability test. Then, the spectral transmittance after performing the following durability test on the sample was measured.
Table 1 shows the average spectral transmittance of 380 to 780 nm before the durability test, the average spectral transmittance of 380 to 780 nm after the durability test, and the difference (%) between them. If the difference is 5.0% or less, it can be said that the deterioration of the dye can be suppressed.
The measurement condition of the spectral transmittance was a double field of view, and a light source of D65 was used. The measurement wavelength interval was 0.5 nm. The light incident surface was the surface opposite to the hard coat layer (separator side).
<Durability test>
The optical laminate was irradiated with ultraviolet rays for 50 hours using a weather resistance tester (manufactured by Suga Test Instruments Co., Ltd., product name "ultraviolet fade meter U48", light source: carbon arc lamp).

2. 2. Fabrication of Optical Laminate [Example 1 of Embodiment 1]
A dye-penetrating ink having the following formulation was applied onto a base material layer (triacetyl cellulose film having a thickness of 60 μm, trade name “TG60UL” manufactured by FUJIFILM Corporation), dried, and the dye was permeated into the base material layer.
Next, the hard coat layer ink 1 of the following formulation was applied (adhesion amount: 5.0 g / m ² ) to the surface of the base material layer opposite to the surface on which the dye penetration ink was applied, dried, and irradiated with ultraviolet rays. A hard coat layer having a thickness of 10 μm was formed to obtain an optical laminate of Example 1. The optical laminate of the first embodiment of the first embodiment includes a hard coat layer and a base material layer (including a dye 1 penetrating from a surface of the base material layer opposite to the hard coat layer) from the outer layer side. Have in order.

<Ink for dye penetration>
-Dye material 1.0 part by mass (manufactured by Yamada Chemical Co., Ltd., trade name: FDG-007, tetraazaporphyrin-based metal compound (organic dye), maximum absorption wavelength: 594 nm)
・ Solvent 1 (methyl ethyl ketone) 60 parts by mass ・ Solvent 2 (methyl isobutyl ketone) 40 parts by mass

<Ink 1 for hard coat layer>
-Radical polymerizable compound 92.0 parts by mass (manufactured by Shin Nakamura Chemical Industry Co., Ltd., trade name: ATM-4PL)
-Photoradical polymerization initiator 5.0 parts by mass (manufactured by IGM Resins, trade name "Omnirad 189")
・ UV absorber 3.0 parts by mass (manufactured by BASF, trade name: Tinuvin477)
・ Solvent 1 (methyl ethyl ketone) 60 parts by mass ・ Solvent 2 (methyl isobutyl ketone) 40 parts by mass

[Embodiment 1 of Embodiment 2]
An ink for resin layer 2 having the following formulation is applied onto a base material layer (triacetyl cellulose film having a thickness of 60 μm, trade name “TG60UL” manufactured by FUJIFILM Corporation) and dried to form a resin layer 2 having a thickness of 5.0 μm. did.
Next, the hard coat layer ink 1 of the above formulation was applied, dried, and irradiated with ultraviolet rays on the surface of the base material layer opposite to the resin layer 2, to form a hard coat layer having a thickness of 5.0 μm. The optical laminate of Example 1 of the second embodiment was obtained. The optical laminate of Example 1 of the second embodiment has a resin layer 2 containing the dye 2, a base material layer, and a hard coat layer (on the opposite side of the resin layer 2) in this order.

<Ink for resin layer 2>
-Non-radical polymerizable thermoplastic resin 99.4 parts by mass (manufactured by Toyobo Co., Ltd., Byron 24SS)
-Dye material 0.6 parts by mass (manufactured by Yamada Chemical, trade name: FDG-007, maximum absorption wavelength: 594 nm)
・ Solvent 1 (methyl ethyl ketone) 50 parts by mass ・ Solvent 2 (methyl isobutyl ketone) 50 parts by mass

[Comparative Example 1]
On the base material layer (triacetyl cellulose film with a thickness of 60 μm, trade name “TG60UL” manufactured by FUJIFILM Corporation), the ink 2 for the hard coat layer of the following formulation is applied, dried, and irradiated with ultraviolet rays on the base material layer. A hard coat layer containing a dye was formed, and an optical laminate of Comparative Example 1 was obtained. The optical laminate of Comparative Example 1 has a base material and a hard coat layer containing a dye in this order.

<Ink 2 for hard coat layer>
-Radical polymerizable compound 91.0 parts by mass (manufactured by Shin Nakamura Chemical Industry Co., Ltd., trade name: ATM-4PL)
-Photoradical polymerization initiator 5.0 parts by mass (manufactured by IGM Resins, trade name "Omnirad 189")
・ Ultraviolet absorber 2.4 parts by mass (manufactured by BASF, trade name: Tinuvin477)
-Dye material 0.6 parts by mass (manufactured by Yamada Chemicals, trade name: FDG-007, maximum absorption wavelength: 594 nm)
・ Solvent 160 parts by mass (methyl isobutyl ketone)
・ Solvent 2 40 parts by mass (propylene glycol monomethyl ether acetate)

From the results in Table 1, it can be confirmed that the optical laminate of the example can suppress the deterioration of the dye and can maintain the visibility for a long period of time.

10: Base material layer 11: Dye non-penetrating region of the base material layer 12: Dye permeation region of the base material layer 21: Resin layer 1
22: Resin layer 2
30: Hard coat layer 70: UV absorber 81: Dye 1
82: Dye 2
100: Optical laminate 110: Display element 120: Image display device

Claims (8)

An optical laminate having a hard coat layer and a substrate layer in this order from the outer layer side, and having at least one of the following configurations (1) and (2).
(1) The base material layer contains a dye 1 that has penetrated from the surface of the base material layer on the side of the hard coat layer or the surface of the base material layer on the side opposite to the hard coat layer, and the base. The resin constituting the material layer is a non-radical polymerizable resin. Further, at least one layer selected from the base material layer and the layer located on the outer layer side of the base material layer contains an ultraviolet absorber.
(2) The optical laminate has a resin layer 2 having a thickness of 5.0 μm or less containing a dye 2 and a binder resin as a layer other than the hard coat layer and the base material layer, and the binder resin is a non-radical polymerizable resin. Is. Further, at least one layer selected from the resin layer 2 and the layer located on the outer layer side of the resin layer 2 contains an ultraviolet absorber. The optical laminate according to claim 1, wherein the hard coat layer contains a radically polymerizable resin. The optical laminate according to claim 1 or 2, wherein the base material layer is an acrylic film or a triacetyl cellulose film. The optical laminate according to any one of claims 1 to 3, wherein the resin layer 2 contains at least one selected from a cured product of a thermoplastic resin and a thermosetting resin composition as a binder resin. The optical laminate according to any one of claims 1 to 4, which has an absorption peak wavelength at least between a wavelength of 470 and 510 nm and a wavelength of 570 and 650 nm. The optical laminate according to any one of claims 1 to 5, wherein the dye 1 and the dye 2 are tetraazaporphyrin-based organic dyes. A polarizing plate having a polarizing element, a transparent protective plate A arranged on one side of the polarizing element, and a transparent protective plate B arranged on the other side of the polarizing element, wherein the transparent protective plate is provided. At least one of the plate A and the transparent protective plate B is the optical laminate according to any one of claims 1 to 6, and the optical is such that the surface on the hard coat layer side faces the opposite side to the polarizing element. A polarizing plate on which a laminate is arranged. An image display device having a display element and the optical laminate according to any one of claims 1 to 6 or the polarizing plate according to claim 7.

Images